Reliably upgrading switch stacks with more that 3 member switches?

[DennisS]

A couple of our large offices have MS355-48X2 stacks with 2 - 5 switch members.  We've gone through several firmware upgrades (currently going from MS 16.9 to MS 17.1.4) and found the stack upgrade behavior is consistent:

Stacks with 2-3 members have a 99% chance of upgrading & rebooting normally

Stacks with 4-5 members will have at least 1 switch that fails to come up without manual intervention

• Break the stack
• Disconnect the impacted switch, hang it behind another switch, power cycle it & hope it upgrades
• Connect it back to the stack and reboot the entire stack

Has anyone had success upgrading large stacks without needing manual intervention, if so, what do you do?

Meraki stacks support up to 6 member switches but what's the point if they can't be upgraded without zero touch.  Majority of our office don't have local IT support.

[RWelch]

By chance, are your organizations/networks setup for Staged Upgrades ?  If so, you might be sure the stack is tagged accordingly.  Maybe at one point each switch (as a standalone) was set to upgrade in certain stages and now they are part of a stack instead?  Not sure if this might be the culprit?

[PhilipDAth]

I don't know the answer.  You could consider rebooting the stacks before the upgrade in case of a slow memory leak or something to get them back into a good state.

I assume you have a complete stack ring configured (every switch has two stacking cables connected)?

[rhbirkelund]

If you are able to reliably reproduce it, perhaps it would be a good idea to open a case, and demonstrate it to Meraki Support?